Scripts for five episodes of BBC's eighth season of Doctor Who have been leaked online and the network is asking fans for their help in preventing the storyline from being spread worldwide.

According to reports the breach in security came from the network's Latin American branch, which needed the scripts to translate the episodes into Spanish.

A press release from BBC Worldwide follows:

BBC Worldwide is currently investigating a security issue around Doctor Who Series 8 where unfinished material has inadvertently been made public. We deeply regret this and apologise to all the show's fans, the BBC and the cast and crew who have worked tirelessly making the series.

We would like to make a plea to anyone who might have any of this material and Spoilers associated with it not to share it with a wider audience so that everyone can enjoy the show as it should be seen when it launches. We know only too well that Doctor Who fans are the best in the world and we thank them for their help with this and their continued loyalty.

The new Doctor will premiere on August 23 at 8:00pm ET. , with a feature-length first episode called "Deep Breath" - starring Peter Capaldi as the Twelfth Doctor and Jenna Coleman as his companion, Clara.

The episode ushers in an exciting new era for the show as Peter Capaldi (The Musketeers, The Thick of It) steps into the role of the Doctor. Fans first got a glimpse of Capaldi's Doctor in November's 50th Anniversary Special, and again in the final minutes of last year's Christmas Special, but the upcoming season premiere marks the first full episode for the Twelfth Doctor.

Capaldi will be joined by Jenna Coleman (Death Comes to Pemberley), who returns as companion Clara Oswald, and Samuel Anderson (History Boys, Gavin & Stacey) who joins the cast as Danny Pink, a teacher at Coal Hill School where Clara also works. Previously announced guest stars include Ben Miller (Primeval, Death in Paradise), Keeley Hawes (Line of Duty, Upstairs, Downstairs), and Tom Riley (Da Vinci's Demons).

Leading up to the premiere, Capaldi and Coleman will appear together in the US for the first time when they arrive in New York on Thursday, August 14 as part of the first ever Doctor Who World Tour. The largest promotional undertaking in the show's 50-year history, the tour will kick off in Cardiff, Wales before heading to London, Seoul, Sydney, New York, Mexico City, and Rio de Janeiro.